Hair treatment composition and methods

ABSTRACT

wherein D is a chromophore; L is a linking group selected from SO 2 , NHCO, and NHSO 2 ; Q is a hydrogen or halogen atom; and R is selected from C 1 -C 4  alkyl, (CH 2 ) n COOH, (CH 2 ) n CONH 2 , (CH 2 ) n SO 3 H, (CH 2 ) n COOM, (CH 2 ) n PO 3 H, (CH 2 ) n OH, (CH 2 ) n SSO 3 ″, (CH 2 ) n NR 1   2 , (CH 2 ) n N + R 1 H 2 , (CH 2 ) n NHCOR 1 , PhSSO 3 ″, PhSO 3 H, PhPO 3 H, PhNR 1   2 , PhN + R 1   3 , (CH 2 ) 2 CH(SH)R 1 (CH 2 ) 3 COOH, and n is an integer in the range of 1 to 4 wherein within the same molecule each n is not necessarily the same integer; M is a cation of an alkaline earth metal, alkali metal, NH4+ or NR 1   3   + ; and R 1  is C 1 -C 4  alkyl.

The present invention relates to compounds suitable for colouringmaterials, in particular keratinous fibre materials, for example hair;to compositions comprising the same, and to methods and uses relatingthereto.

In a preferred embodiment the invention relates to a process ofcolouring keratinous fibre materials, for example hair, and thenoptionally removing colour from the material, whilst limiting damage tothe material. The colouring and colour removal stages can be carried outin quick succession or with a reasonable time period in-between them.The colouring and colour removal stages can be repeated many times, withlimited damage to the material, for example hair.

The desire to alter the colour of human hair is not a facet of moderntimes. Since the days of the Roman Empire the colour of human hair hasbeen routinely altered to accommodate the changes of fashion and style.However the attainment of precise initial colours which are retained bythe hair for a desirable period has remained a more elusive goal. Thedifficulties in the development of hair colouring compositions which candeliver precise long-lasting colours are in part due to the inherentstructure of the hair itself and in part due to the necessary conditionsof effective hair colouration processes.

In general, the condition and structure of human hair is not regularalong the length of the hair shaft. Human hair is subject to variouschemical and mechanical treatments, for example combing, brushing,shampooing, heating, perming and straightening as well as exposure tothe sun. As such, the hair at the ends of the hair shaft will generallyexhibit greater signs of damage relative to the new growth close to thescalp. This damage can lead to inconsistent colouration when the hair isdyed due to irregular uptake of the hair colouring agents along thelength of the hair shaft.

Once the hair has been coloured there is a desire for the colour to beresistant to fading, as occasioned by the actions of washing (also knownas wash fastness), perspiration, hair spray and other exterior factorssuch as the action of the sun, and further that the colour be retainedin a consistent manner for a predictable period of time. Additionallydamage to the hair that can lead to irregular dye uptake as discussedabove, can lead to increased fading of the damaged portions of the hairand consequently, irregular levels of colour fade over time. Anadditional difficulty commonly associated with the dyeing of human hairis the need for dye systems which avoid any adverse effect on the hairand skin of the user, such as brittle hair, or, irritation of the skin,or, staining (colouring) of the skin.

Thus, it would be desirable to develop a hair colouring compositionwhich exhibits reduced fade, provides improved resistance to wash outduring a regular cleansing regime, can deliver substantially consistenthair colour results throughout the hair, which has reduced irritanteffect on the skin, which has reduced staining on the skin, which hasreduced adverse effects on the hair of the user and also to develop aconvenient and easy-to-use method for the delivery of such a haircolouring composition to the hair.

Although it is desirable to provide hair colouring compositions whichare resistant to fade, on occasions a user may wish to remove colourfrom dyed hair. Currently if this is desired, it is necessary to treatthe dyed hair with oxidising bleaches. However, repeated colouring andoxidative bleaching of the dyed hair can lead to significantly damagedhair. It would thus be highly desirable to provide a hair colouringcomposition which could easily be removed from the hair withoutoxidatively bleaching the dyed hair and thus limiting any damage to thehair.

Over the years significant effort has been directed towards theelimination of many of the problems associated with the dyeing of humanhair. Various approaches to hair dyeing have been developed includingthe use of oxidative dyes, direct action dyes, natural dyes, metallicdyes and reactive dyes.

Reactive dye hair colouring agents can be used to deliver a variety ofhair colours to the hair.

However substantial improvement is needed in the areas of coloursaturation colour development, precise initial colour consistency,improved wash fastness, improved hair condition and reduced levels ofhair damage. It is also necessary to consider the environmental impactof chemicals used as hair colouring agents.

Thus there is a need for reactive dye hair colouring compounds andcompositions which show improved properties compared with those of theprior art. Facility to dye other keratinous fibres, for example wool,cashmere, mohair and alpaca, would be an advantage.

According to a first aspect of the present invention there is providedcompounds of formula (I)

D-L-CHQ-CH₂—SR   (I)

wherein D is a chromophore; L is a linking group selected from SO₂,NHCO, and NHSO₂; Q is a hydrogen or halogen atom; and R is selected fromC₁-C₄ alkyl, (CH₂)_(n)COOH, (CH₂)_(n)CONH₂, (CH₂)_(n)SO₃H,(CH₂)_(n)COOM, (CH₂)_(n)PO₃H, (CH₂)_(n)OH, (CH₂)_(n)SSO₃ ⁻, (CH₂)_(n)NR¹₂, (CH₂)_(n)N⁺R¹H₂, (CH₂)_(n)NHCOR¹, PhSSO₃ ⁻, PhSO₃H, PhPO₃H, PhNR¹ ₂,PhN⁺R¹ ₃, (CH₂)₂CH(SH)R¹(CH₂)₃COOH, and

n is an integer in the range of 1 to 4 wherein within the same moleculeeach n is not necessarily the same integer; M is a cation of an alkalineearth metal, alkali metal, NH₄ ⁺ or NR¹ ₃ ⁺; and R¹ is C₁-C₄ alkyl.

When there is more than one group R¹ within a molecule each may be thesame or different.

One preferred sub-class of compounds of formula (I) may be defined as

D-L-CH₂CH₂—SR   (IA)

where D, L and R are as defined above.

Another preferred sub-class of compounds of formula (I) may be definedas

D-L′-CHQ-CH₂—SR   (IB)

where D, Q and R are as defined above and L′ represents a linking groupNHCO. In this sub-class Q is preferably a halogen atom.

Esters and salts of the acidic residue compounds falling within theabove definition are also within the scope of the present invention.

Linking group L is preferably selected from SO₂ and NHCO. SO₂ isespecially preferred.

A halogen atom (Hal) is suitably a fluorine, chlorine, bromine or iodineatom; preferably a chlorine or, especially, a bromine atom.

The use of such compounds as colouring agents for keratinous fibrematerials, notably hair, have shown a number of benefits, for exampleimproved wash fastness of dye on fibres, less colour fade over time,improved consumer acceptance, improved colour consistency andsaturation, improved fibre condition, reduction in fibre damage and skinirritation, and an improved health and safety and/or environmentalprofile.

The novel compounds of the present invention comprise a thioether bondedto an ethylene group which at the other terminus is bonded to a linkinggroup, for example the carbon atom of an amide or a sulfur atom ofsulfone. The linking group is in turn bonded to a chromophore moiety,preferably to a carbon atom thereof.

The group SR in formula I is preferably SCHR²R³.

In preferred embodiments compounds of the present invention have astructure shown in formula (II) or (IIA).

D-L-CH₂—CH₂—SCHR²R³   (II)

D-L′-CH(Hal)-CH₂—SCHR²R³   (IIA)

where D, L, L′ and Hal are as defined above.

Preferably R² is selected from (CH₂)_(m)COOX, (CH₂)_(m)SO₃X,(CH₂)_(m)NH₂, (CH₂)_(m)NR⁴R⁵, (CH₂)_(m)NHCOR⁴ and (CH₂)_(m)CH(COOX)NH₂;wherein m is an integer of from 0 to 3, and X is selected from hydrogen,an alkali metal, a C₁ to C₄ alkyl group and a substituted orunsubstituted ammonium salt; R⁴ is a C₁ to C₄ alkyl group and R⁵ isselected from hydrogen and a C₁ to C₄ alkyl group.

Preferably m is 0 or 1. X is preferably selected from hydrogen, sodium,potassium, NH₄ or NH(R⁶)₃ wherein each R⁶ is a C₁ to C₄ alkyl, forexample methyl.

R³ is preferably selected from hydrogen, an alkyl group having 1 to 4carbon atoms, an ester, an acid, an amide, an amine residue or analcohol residue.

Especially preferred compounds of the present invention are those offormulae (III) and (IV):

D-SO₂—CH₂—CH₂—SCH₂COOH   (III)

D-SO₂—CH₂—CH₂—SCH₂CH(COOH)NH₂   (IV)

and esters and salts thereof. Suitable esters include methyl and ethylesters. Suitable salts include alkali metal and ammonium salts.

The compounds of the present invention include a chromophore moiety D.

Any chromophore moieties suitable for use for dyeing substrates can beused in the present invention. The term chromophore as used herein meansany photoactive compound and includes any coloured or non-coloured lightabsorbing species, e.g. fluorescent brighteners, UV absorbers, IRabsorbing dyes.

Suitable chromophore moieties for use in the dye compounds hereininclude the radicals of monoazo, bisazo or polyazo dyes or of heavymetal complex azo dye derived therefrom or of an anthraquinone,phthalocyanine, formazan, azomethine, dioxazine, phenazine, stilbene,triphenylmethane, xanthene, thioxanthene, nitroaryl, naphthoquinone,pyrenequinone or perylenetetracarbimide dye. Most preferred for dyeinghair in the short times and low temperatures favoured by the presentinvention are those chromophores which have a molecular mass of lessthan 1500.

Suitable chromophore moieties for use in the dye compounds hereininclude those disclosed in EP-A-0,735,107 (Ciba-Geigy), incorporatedherein by reference, including the radicals described therein whichcontain substituents customary for organic dyes, such as sulfonatesubstituents which enhance the water-soluble properties of the dyecompound.

Preferred chromophore moieties D are those based on azo compounds,anthraquinone dyes or phthalocyanine dyes.

Preferred azo chromophore moieties for use in the present inventioninclude monoazo species of formula (V) and bisazo species of formula(VI).

Ar¹—N═N—Ar²-L   (V)

X—Ar³—N═N—Ar⁴—N′N—Ar⁵-L   (VI)

It is indicated by the dashed lines in the structures which part of eachmolecule is bonded to linking group L.

Each of Ar¹, Ar², Ar³, Ar⁴ and Ar⁵ independently represent anoptionally-substituted aromatic residue. These may be based on one ormore aromatic ring structures preferably selected from benzene,naphthalene, anthracene, phenanthrene, piperidine, imidazole, parazole,pyrazalone, oxazole, thiophene, benzopyrene, quinoline, isoquinoline,chromine, isochromine, indole, isoindole, benzofuran, benzamidazole andpyrazole.

In some embodiments as detailed above the aromatic residue may comprisea fused ring system. Alternatively each or any of Ar¹, Ar², Ar³, Ar⁴ andAr⁵ may comprise two or more aromatic rings linked together via a singlecovalent bond.

In preferred embodiments each of Ar¹, Ar², Ar³, Ar⁴ and Ar⁵ isindependently selected from structures based on benzene, naphthene,pyrazole and adducts thereof.

Any of said aromatic moieties Ar¹, Ar², Ar³, Ar⁴ and Ar⁵ may besubstituted with one or more substituents selected from hydroxy, nitro,amino, amido, COON, halo, ether, thioether, sulfoxyl, cyano, thiocyano,ester and alkyl, for example methyl.

Preferably at least one of Ar¹ and Ar² in structure (V) is substitutedwith a group SO₃Y, wherein Y is hydrogen or an alkali metal or ammoniumsalt. Preferably Y is sodium. Each of Ar¹ and Ar² may include suchsulfonate residues. Either or both of Ar¹ and Ar² may be polysulfonated,that is either or each may include more than one SO₃Y residues.

In structure (VI), each or any of Ar³, Ar⁴ and Ar⁵ may be optionallysubstituted with one or more residues selected from amino, hydroxy,amido, COON, ester, thioether, sulfoxy, cyano, thiocyano, ether,thioether, halo and alkyl for example methyl. Preferably at least one ofAr³, Ar⁴ and Ar⁵ is sulfonated.

In structure (VI) X may be selected from hydrogen, hydroxide, nitro,amino, ester, COON, ether, amido, halo, alkyl, alkoxy, sulfoxy andthioether. Preferably X is a second group of the formula LCH₂CH₂SR.

Preferred anthraquinone chromophore moieties are those of formula (VII)

wherein n is from 0 to 6, m is from 0 to 6, X is selected from hydrogenand alkali metal and Y is selected from hydroxy, amino, amido, COON,ether, ester, thioether or sulfoxy, alkyl, halo or nitro. Thesubstituents Y and SO₃X may be present on either or each of the benzenerings. In preferred embodiments n is 1 or 2, m is 1 or 2, X is sodiumand Y is NHCOCH₃, CH₃ or OH. Ar represents an aromatic residue,preferably a benzene residue which, as indicated by the dashed bond, issubstituted with the group L-CH₂CH₂SR.

Anthraquinone dyes are useful for providing light fast blue chromophoremoieties. Especially preferred compounds are those having 1,4-diamino or1,4-substituted diamino derivatives. The sulfo group is preferably atthe 2-position.

Preferred phthalocyanine dyes are those based on copper phthalocyanine,especially sulfonated or polysulfonated residues thereof. Thesecompounds provide chromophores of brilliant turquoise blues and emeraldgreens. An example of such a compound is shown in formula (VIII).

Other such copper phthalocyanine compounds may be monosulfonated,disulfonated or trisulfonated. The above compounds are converted to thesulfonyl chloride and then reacted with m-base(1-aminobenzene-3-sulfatoethylsulfone) or p-base(1-aminobenzene-4-sulfatoethylsulfone) under mild alkaline aqueousconditions to provide a mixture including sulfatoethylsulfone compounds.Subsequent reaction with an appropriate thiol provides compounds of thepresent invention having the formula(RSCH₂CH₂SO₂—Ar—NHSO₂)₁₋₃CuPc-(SO₃H)₁₋₃ where CuPc is a copperphthalocyanine residue.

Especially preferred chromophore groups D for use herein are thosepresent in Remazol® dyes commercially available from Dystar. Compoundsof this type, incorporating such chromophore moieties, are believed tobe denoted by representative formulae IXa, IXb, IXc, IXd and IXe.

The compounds of formula IXa is orange, that of IXb is blue, that of IXcis black, that of IXd is red and that of IXe is yellow. It will beappreciated that the formation of mixtures of two or more of thesecompounds in differing amounts enables a wide variety of colours to beobtained.

According to a second aspect of the present invention there is provideda method of preparing compounds of the first aspect, the methodcomprising reacting a compound of formula (X) or (X′) with a thiol offormula (XI):

wherein R, D and L are as defined in relation to the first aspect and Yis a leaving group.

Y is preferably selected from a halogen, especially chlorine, OPO₃H,OSO₃H, SSO₃H and NR¹R²R³, where R¹ and R² are C₁₋₄ alkyl and R³ ishydrogen or C₁₋₄ alkyl.

The compounds of formula X or X′ may be regarded as dye precursormaterials.

In the method of the second aspect the compounds of formula X or X′ aresuitably reacted with the thiol XI under standard reaction conditions.Such conditions will readily be understood by those skilled in the art.

Typically, these reactions are carried out at a temperature of from −10to 70° C., preferably from 0 to 60° C., for example between 20 and 50°C.

Suitably the reaction is carried out at a pH of between 6 and 12,preferably from 7 to 11.

A preferred solvent for carrying out the reaction of the second aspectis water.

The reaction may be carried out in a mixed aqueous solvent system, forexample an aqueous alcoholic solution or a mixture of water and DMF.

The method of the second aspect may be used to prepare a mixture ofcompounds of the first aspect. In such cases the method may comprisereacting two or more compounds of formula X and/or X′ with one or morethiols of formula XI; or reacting one or more compounds of formula Xand/or X′ with two or more thiols of formula XI. The mixture of theproducts obtained will be related to the mixture of reactants and may beadjusted according to the colour and other desired properties of theproduct.

Compounds of formula X and X′ are known classes of compounds and may bemade by methods known in the art, or by analogous methods. The compoundsin which L comprises the group SO₂ have been used or proposed aschromophore-containing precursors for many dye molecules (not having theterminal group —SR), as have the compounds containing the group NHCO.For example GB 1037648 and GB 1351976 may be cited as describingapplicable methods. Useful background may also be found in the book“Wool Dyeing”, Ed. D. M. Lewis, Society of Dyers and Colourists,Bradford, 1992, pp. 225-227.

According to a third aspect of the present invention there is provided acomposition for colouring a material, comprising one or more compoundsof the first aspect, an optional diluent (or carrier) and furtheroptional ingredients.

Preferably the composition is a composition for colouring a keratinousmaterial. More preferably it is a composition for colouring a keratinousfibre material, although it may also be used to dye non-fibrous keratinbased material, for example fingernails.

A keratinous fibre material may be derived from an animal's coat or pelt(for example wool, or cashmere, or mohair, or angora or alpaca) but ispreferably human hair. For convenience the word “hair” is used hereafterbut it is to be understood that the invention is broader in its scopeand that the following definitions apply to materials in general.

The composition may be provided as a concentrated composition which upondilution can be applied to the hair to provide the desired colour. Insome embodiments, the composition may consist essentially of a mixtureof two or more compounds of the first aspect.

In preferred embodiments the composition of the third aspect comprises aready-to-use formulation which can be directly applied to hair to effectthe dyeing thereof.

The ready-to-use hair colouring formulations of the present inventionpreferably comprise at least 0.001 wt % of one or more compounds of thefirst aspect, preferably at least 0.005 wt %, more preferably at least0.01 wt %, preferably at least 0.05 wt % and most preferably at least0.1 wt %. Such formulations may comprise up to 25 wt % of one or morecompounds of the first aspect, for example up to 20 wt % or 15 wt %,preferably up to 10 wt %, more preferably up to 7 wt %, preferably up to5 wt % and most preferably up to 3 wt %.

The types and levels of dyes used in each composition will depend uponthe desired hair shade.

In addition to compounds of the first aspect, the composition of thethird aspect may include one or more further ingredients. Suchingredients include a second thiol component, a pH control agent, athickener, one or more surfactants, other dye materials and furtheradditives as described herein. A diluent may suitably be included. Thediluent may be present in compositions provided in concentrated form. Adiluent is present in embodiments in which the composition is providedas a ready-to-use formulation.

The composition of the third aspect of the present invention ispreferably provided as a stable composition. Such a composition maysuitably be stored without significant decomposition thereof underambient conditions in a sealed container for a period of at least aweek, preferably at least a month, more preferably at least six months.

Preferably the compositions of the third aspect comprise a second thiolcomponent. This is present in addition to the necessary amount of thiolof formula XI (typically one molar equivalent) which is reacted with thedye precursor of formula X or X′. In some embodiments the second thiolcomponent may be the same as the thiol of formula XI. Thus in preferredembodiments a molar excess of total thiol (including the thiol offormula XI and the second thiol component) is provided. The molar ratioof total thiol (of formula XI and second thiol component) to dyeprecursor of formula X or X′ is preferably at least 1.05:1, morepreferably at least 1.1:1, for example at least 1.2:1, 1.5:1 or 2:1. Itmay be at least 5:1, or at least 10:1.

Suitably sufficient excess thiol is added such that when dyeing hairsurface reduction of cystine disulfide to cysteine thiol is achieved.Without being bound by theory it is believed that cysteine thiolfunctions as the main reactive nucleophile that reacts with the dyecompounds of the present invention. An additional benefit of usingthiols is that they may open up the hair structure and allow penetrationof other agents, including dyes.

As detailed above, the thiol of formula XI may comprise a mixture ofthiols. The second thiol component may comprise a single thiol or amixture of thiols which may include compounds which are the same ordifferent to the thiols of formula XI.

Examples of suitable thiols for use as the second thiol componentinclude thioglycolic acid, thiolactic acid, dihydrolipoate,thioglycerol, mercaptopropionic acid, cysteine, N-substituted cysteines,cysteamines, N-substituted cysteamines, thioethanol and 1-thiopropane3-sulfonate. Thioglycolic acid is especially preferred.

Preferably the second thiol component is present in an amount of from0.5 to 20% wt of the composition, preferably 1 to 15% wt, morepreferably 1.5 to 10% wt. In the case when a second thiol component isthe same compound as a thiol of formula (XI) these weight definitionsrefer to the amount of free thiol in the composition, i.e. thiol notconsumed in the reaction between compounds (X) or (X′), and (XI).

Alternatively and/or additionally the hair colouring composition mayfurther comprise a sulfite salt. This may in some embodiments replacesome or all of the second thiol component. Preferred sulfite salts arealkali metal or ammonium salts. Most preferred is sodium sulfite.

The sulfite salt when present is preferably present in an amount of from0.1 to 15 wt %, preferably from 0.5 to 10 wt %, more preferably from 1to 5 wt %.

Another preferred ingredient herein is a substance which disruptshydrogen bonding in the composition (a hydrogen bond breaker). Anyhydrogen bond breaker suitable for use in a hair dye composition can beused herein. Suitable examples include lithium bromide, urea,resorcinol, catechol, dihydroxyacetone, formamide, potassium chlorideand magnesium chloride. Particularly preferred for use herein is urea.

The colouring compositions of the present invention preferably have a pHin the range of from about 6 to about 11, preferably from about 7 toabout 10.5, preferably about 9 to about 10.5. In order to maintain sucha pH the compositions may contain one or more optional pH controlagents.

Examples of alkaline pH control agents suitable for use in the presentinvention include ammonium hydroxide, ethylamine, dipropylamine,triethylamine and alkanediamines such as 1,3-diaminopropane, alkalinealkanolamines such as mono, di or tri-ethanolamine, preferably thosewhich are completely substituted on the amine group such asdimethylaminoethanol, polyalkylene polyamines such as diethylenetriamineor a heterocyclic amine such as morpholine as well as the hydroxides ofalkali metals, such as sodium and potassium hydroxide, hydroxides ofalkali earth metals, such as magnesium and calcium hydroxide, basicamino acids such as alanine, leucine, iso-leucine, and histidine andalkanolamines such as dimethylaminoethanol, aminoalkylpropanediol andmixtures thereof. Preferred pH control agents include water solublebases, for example carbonates and hydroxides of alkali metals andammonium, and triethanolamine.

Especially preferred pH control agents for use herein include2-amino-2-methyl-1-propanol, ammonium hydroxide, and sodium hydroxide.

The hair colouring compositions of the present invention mayadditionally include a thickener, suitably a cosmetically approvedthickener, at a level of from about 0.05% to about 20%, preferably fromabout 0.1% to about 10%, more preferably from about 0.5% to about 5% byweight. Thickening agents suitable for use in the compositions hereininclude those specified for cosmetic use by the Scientific Committee onConsumer Products (SCCP) managed by the Directorate-General for Healthand Consumer Protection of the European Commission. The SCCP approve alist of chemicals for use which is referred to as the INCI list(International Nomenclature of Cosmetic Ingredients list). Preferredthickening agents suitable for use in the compositions of the presentinvention include oleic acid, cetyl alcohol, oleyl alcohol, sodiumchloride, cetearyl alcohol, stearyl alcohol, synthetic thickeners suchas Carbopol, Aculyn and Acrosyl and mixtures thereof. Preferredthickeners for use herein are Aculyn 22®, steareth-20 methacrylatecopolymer; Aculyn 44®, polyurethane resin and Acusol 830® acrylatecopolymers which are available from Rohm and Haas, Philadelphia, Pa.,USA. Additional thickening agents suitable for use herein include sodiumalginate or gum arabic, or cellulose derivatives, such as methylcellulose or the sodium salt of carboxymethylcellulose or some types ofacrylic polymers.

The hair colouring compositions of the third aspect optionally containurea. Without being bound by theory it is believed that urea helps tosolubilise the dye compounds in the composition and/or denaturekeratinous proteins found in hair (and animal fibres) and increases therate of reaction with the fibre substrate.

Urea may suitably be present in an amount of at least 2% wt of thecomposition, and preferably at least 5% wt.

Urea may suitably be present in an amount up to 30% wt of thecomposition, preferably up to 20% wt, most preferably up to 15% wt.

Suitable diluent materials for use in compositions of the presentinvention may be selected from the INCI list. Water is the preferreddiluent for use in compositions of the present invention. However, suchcompositions may include one or more further solvents as additionaldiluent materials. Generally, solvents suitable for use in the colouringcompositions of the present invention are selected to be miscible withwater and innocuous to the skin. Solvents suitable for use as additionaldiluents herein include C1-C20 mono- or polyhydric alcohols and theirethers, glycerine, with monohydric and dihydric alcohols and theirethers preferred. In these compounds, alcoholic residues containing 2 to10 carbon atoms are preferred. Thus, a preferred group of suitablediluents includes ethanol, isopropanol, n-propanol, butanol, propyleneglycol, ethylene glycol monoethyl ether, and mixtures thereof. Water isthe preferred principal diluent in the compositions of the presentinvention. Principal diluent, as defined herein, means, that the levelof water present is higher than the total level of any other diluents.

The diluent is present at a level preferably of from about 5% to about99.98%, preferably from about 15% to about 99.5%, more preferably fromabout 30% to about 99%, and especially from about 50% to about 98% byweight of the compositions herein.

In preferred embodiments, the diluent comprises at least 90 wt % water,more preferably at least 95 wt %. Suitably the diluent consistsessentially of water.

The compositions of the present invention can additionally contain asurfactant system. Suitable surfactants for use in compositions of thepresent invention may be found on the INCI list. Suitable surfactantsfor inclusion in the compositions of the invention generally have alipophilic chain length of from about 8 to about 22 carbon atoms and canbe selected from anionic, cationic, nonionic, amphoteric, zwitterionicsurfactants and mixtures thereof.

Suitable surfactant compounds for use in the present invention are ofthe conventional type known for use in hair dye formulations and will bewell understood by those skilled in the art. Preferred surfactants arethose favoured by the cosmetic industry, for example cocamidopropylbetaine which is gentle and non-allergenic.

The hair colouring compositions of the present invention may, inaddition to the compounds of formula I, optionally include other dyematerials (suitable options may be found on the INCI list). Optionalother dyes suitable for use in the hair colouring compositions andprocesses according to the present invention include bothsemi-permanent, temporary and other dyes.

Non-oxidative dyes as defined herein include the so-called ‘directaction dyes’, metallic dyes, metal chelate dyes, fibre reactive dyes andother synthetic and natural dyes. Various types of non-oxidative dyesare detailed in: ‘Chemical and Physical Behaviour of Human Hair’ 3rd Ed.by Clarence Robbins (pp 250-259); ‘The Chemistry and Manufacture ofCosmetics’. Volume IV. 2nd Ed. Maison G. De Navarre at chapter 45 by G.S. Kass (pp 841-920); ‘cosmetics: Science and Technology’ 2nd Ed., Vol.II Balsam Sagarin, Chapter 23 by F. E. Wall (pp 279-343); ‘The Scienceof Hair Care’ edited by C. Zviak, Chapter 7 (pp 235-261) and “HairDyes”, J. C. Johnson, Noyes Data Corp., Park Ridge, U.S.A. (1973), (pp3-91 and 113-139).

A number of additional optional materials can be added to the colouringcompositions herein described each at a level of from about 0.001% toabout 5%, preferably from about 0.01% to about 3%, more preferably fromabout 0.05% to about 2% by weight of composition. Such materials includeproteins and polypeptides and derivatives thereof; water-soluble orsolubilisable preservatives; moisturising agents; anti-bacterial agents;low temperature phase modifiers; viscosity control agents; quaternaryamine compounds; hair conditioning agents; enzyme stabilisers; colouringagents; TiO₂ and TiO₂-coated mica; perfumes and perfume solubilisers;zeolites; Ca²⁺/Mg²⁺ sequestrants and water softening agents. A number ofother formulation ingredients could be added to the composition, forexample one or more of stabilisers, emulsion stabilisers, film formers,emulsifiers, antioxidants, chelators, antistatic agents, anti-cakingagents, pH buffers, bulking agents, UV absorbers, moisturising agents,opacifiers, masking agents, reducing agents, humectants and foamingagents.

Examples of suitable compounds which may be used for such functions arewell known to those skilled in the art and are preferably selected fromthose commonly used in hair dye formulations. A suitable reference pointfor lists of such materials can be found in the INCI list.

According to a fourth aspect of the present invention there is provideda method of preparing a composition of the third aspect, the methodcomprising mixing together one or more compounds of the first aspectwith an optional diluent and further optional ingredients

The amount of each compound of the first aspect which is used willdepend on the exact colour that is desired. It will be appreciated thatvarying the number of, type and amount of each coloured compound willvary the overall colour of the composition thus obtained.

In preferred embodiments in which the composition of the third aspect isprovided as a ready-to-use formulation, the method of the fourth aspectmay comprise adding to a diluent one or more compounds of the firstaspect.

Alternatively the method of the fourth aspect may comprise adding to adiluent a one or more precursor materials of formula X or X′ and one ormore thiols of formula XI.

In some preferred embodiments the method of the fourth aspect comprisesadding to a diluent a thiol and commercially-available chromophoremoiety having appended thereto a vinyl sulfone residue. Examples of suchcompounds are those sold under the trademark Remazol by Dystar UK andpreferred compounds include precursor materials described in relation tothe second aspect.

The thiol is preferably a compound of formula R²R³CH₂SH wherein R² andR³ are as defined in relation to the first aspect. Most preferably thethiol is selected from thioglycolic acid, cysteine, cysteamine,N-substituted cysteamines, thioethanol, 1-thiopropane 3-sulfonate andmixtures thereof. Suitable N-substituted cysteamines include compoundsof formula HSCH₂CH₂NR⁴R⁵ and HSCH₂CH₂NHCOR⁴ wherein R⁴ may be C₁ to C₄alkyl and R⁵ may be hydrogen or C₁ to C₄ alkyl.

In such embodiments the compounds of the first aspect are formed in situwhen the thiol and precursor material are added to the diluent.

Preferably an excess of thiol is added. As described in relation to thethird aspect, by excess thiol we mean that a molar excess of total thiolis present when comparing the total amount of thiol to the total amountof precursor materials X or X′. The total thiol includes thiol(s) offormula XI and a second thiol component which may or may not be the sameas the thiol(s) of formula XI. In some embodiments the method of thefourth aspect may comprise mixing together approximately equimolaramounts of one or more precursor materials of formula X or X′ and one ormore thiols of formula XI; allowing these materials to react for asuitable period; and then adding a second thiol component. In preferredembodiments the method of the fourth aspect comprises mixing togetherone or more precursor materials of formula X or X′ with a molar excessof one or more thiols of formula XI.

In embodiments in which the compounds of the first aspect are formed insitu when the thiol and precursor material are added to a diluent,preferably the total amount of thiol (including any second thiolcomponent) added to the diluent is at least 0.01 wt %, preferably atleast 0.1 wt %, more preferably at least 0.5 wt %, for example at least0.8 wt %, preferably at least 1 wt % and most preferably at least 1.2 wt%. In such embodiments, the total amount of thiol added to the diluentmay be up to 20 wt %, for example up to 15 wt % or up to 10 wt %.Preferably it is up to 8 wt %, more preferably up to 5 wt %, preferablyup to 3wt %. The above definitions apply to the total amount of allthiol compounds in embodiments in which mixtures are present.

In such embodiments in which a precursor material is added to a diluent,this is added in an amount of at least 0.01 wt %, preferably at least0.05 wt %, for example at least 0.1 wt % or at least 0.5 wt %. Theprecursor may be added in an amount of up to 10 wt %, for example up to5 wt % or up to 3wt %. The above definitions apply to the total amountof all precursor materials in embodiments in which mixtures are present.

According to a fifth aspect of the present invention there is provided apackaged fibre colouring product comprising a colouring compositioncomprising compounds of the first aspect or precursors therefor andpackaging for said colouring composition.

Any suitable packaging for delivering the reactive dye compounds andcompositions of the present invention could be used. Examples ofsuitable packaging include bottles, pump foamers, and the like.Preferably the packaging is sealed and provides an airtight seal priorto use.

A packaged hair colouring product of the fifth aspect may be a kitcomprising a plurality of separate compounds of the first aspect, orprecursors thereof. The kit may comprise instructions regarding theco-use of such colouring compositions. They may be used together, forexample: by blending them prior to application to hair; or by applyingthem zonally to hair so as to obtain contrast effects, such as streaks;or by applying them sequentially over the same regions of hair so as tocreate an appearance of depth or texture in the hair (as opposed to moreeven appearance which may be produced by one hair colouringcomposition).

In a packaged fibre (e.g. hair) colouring product of the fifth aspectthe product may comprise separate compounds of the first aspect.Alternatively it may comprise precursor compounds which upon admixtureprior to application to the fibre substrate form a compound of the firstaspect of the present invention. In the case of the kit, it may comprisea plurality of dye-carrying precursors or compositions and a commonreactant therefor (for example a compound of formula (XI) as identifiedabove).

Thus, a packaged colouring product of the present invention may comprisea first composition comprising one or more compounds of formula X or X′and a second composition comprising one or more thiols of formula XI.These compositions may suitably be provided in a form such thatadmixture thereof prior to application to the fibre substrate provides acomposition of the third aspect.

In embodiments in which the packaged colouring product comprises twoprecursor compositions, each composition is individually packaged,preferably in a sealed container. Preferably the second packagedprecursor composition comprising one or more thiols of formula XIcomprises a molar excess of said compounds compared to the total numberof moles of one or more compounds of formula X or X′ provided in thefirst packaged precursor composition.

Suitably simple admixture of the first precursor composition and secondprecursor composition provides a composition of the third aspect whichis ready-to-use. Optional additional ingredients may be included ineither the first precursor composition or the second precursorcomposition or both of these. Such additional ingredients include forexample a pH control agent, a thickener and other ingredients, such asdescribed in relation to the third aspect.

In embodiments in which the packaged colouring product comprises a firstprecursor composition and a second precursor composition, each precursormay comprise part of a bi-component thickening system such that mixingof the two precursor compositions provides a colouring composition ofincreased viscosity.

Such a thickening system may involve a change of pH on mixing of the twoprecursor compositions, which will then affect the viscosity of theresultant composition. Bi-component thickening systems may work indifferent ways but most commonly a change in pH is involved. For exampleone component may comprise a material, for example as sold by Rohm &Haas under the trade mark Aculyn 22 which is of low viscosity and afree-flowing liquid at low pH (e.g. pH 4) but which increases inviscosity to form a thick paste when the pH is increased (e.g. to pH8.5).

The properties sought in a thickener system are those which provide thecomposition with a suitable viscosity profile in order for it to spreadacross the head easily during the hair dyeing process, and then stay inposition on the head when required. The choice of thickening agent orbi-component thickening agent is dependant on the additional componentswithin a composition, and such choices are well known to those skilledin the art. Suitable materials can be found on the INCI list.

Packaged fibre colouring compositions of the present invention maysuitably further comprise instructions for application e.g. to hair.They may also include instructions for mixing two or more precursorcompositions.

The packaged fibre colouring product of the present invention maycomprise a plurality of portions of a composition of the third aspect,or a plurality of portions of precursor compositions. Each such portionmay be suitable for a single colouring application.

According to a sixth aspect of the present invention there is provided amethod of dyeing fibres (e.g. hair), the method comprising applying tothe fibres a composition of the third aspect.

Preferably the method of the sixth aspect is a method of dyeing humanhair. Suitably the method comprises applying to the hair the compositionat a temperature of between 0° C. and 60° C., for example at atemperature of between 15° C. and 50° C. preferably between 20° C. and45° C. Suitably the composition applied to the hair has a pH of between6 and 11, preferably 7 and 10.5, preferably 9 and 10.5. When dyeinghuman hair at temperatures above ambient temperatures a suitable hoodcan be employed to achieve the required temperature.

Further preferred features of the composition are as defined in relationto the third aspect. Preferably in the method of the sixth aspect thecomposition of the third aspect is applied to the hair (preferably the“live”—that is, growing—hair on the head of a human) to provide completeor partial coverage, as desired, and left on the hair for a period of atleast 30 seconds, for example at least 1 minute or at least 2 minutes.The composition may be left on the hair for a period of up to 2 hours,for example up to 90 minutes, or up to 60 minutes, up to 45 minutes orup to 30 minutes.

A particular advantage of the present invention is that it allows thecolouring of hair to be achieved in a relatively short period, forexample from 3 to 20 minutes or 5 to 10 minutes.

Preferably following this period the composition may be rinsed from thehair with water. Suitably it is rinsed with water until the water runsclear and no further colour is rinsed away. In some preferredembodiments the hair is then rinsed with a mildly acidic solution ofhydrogen peroxide (preferably of pH 3-6.5, preferably 4.5-5.5), andpreferably left for a dwell time of 2-30 minutes, preferably 5-15minutes; before being again rinsed with water.

Hair treated by the method of the sixth aspect is found to have evencolour distribution, and reduced damage to hair is observed.

Further, it has been observed that the colouring compositions of thepresent invention provide superior wash fastness compared to those ofthe prior art. For example, following twenty shampooing applicationshair coloured by a typical “permanent” colouring composition of theprior art would show some colour fading. However hair coloured by thecompositions of the present invention shows substantially no fadingafter twenty washes.

The method of the sixth aspect of the present invention is preferably amethod of colouring human hair, growing on the head. Such a method mayinclude a first step of bleaching the hair prior to adding a compositionof the third aspect to provide a lighter initial colour and a differentoverall result.

This first bleaching step may be carried out by use of percarbamic acidand/or a diacyl percarbamate, generated in situ by the method of theapplicant's earlier patent EP 1313830B; or by another standard bleachingmethod of the prior art.

If it is desired to remove the colour from the hair following thecolouring method of the sixth aspect of the present invention, thiscould be achieved by applying to the hair a composition comprising achemical agent able to reduce the chromophore moiety. Such compositionsare well known to those skilled in the art and the removal of the colourin such circumstances is readily achieved.

However, the present inventors have developed a particularly effectivecomposition and method which can be used to remove colour from dyedhair. The method is effective at removing hair dyed using oxidative hairdye compositions of the prior art. However it is particularly effectiveat removing colour from hair treated according to the method of thesixth aspect. Thus, the present invention may further provide a haircolour removal method.

The colour removal method is not a bleaching method. Indeed the colourremoval method of the present invention is particularly advantageousbecause it does not involve oxidative bleaching of the hair and thusavoids the damage that colour removal by bleaching may cause.

The colour removal method of the present invention can be used to removecolour that has been applied to the hair using the method of the sixthaspect, or it may be used to remove colour from hair which has been dyedusing an oxidative dye of the prior art. Such dyes are known to thoseskilled in the art. Examples of oxidative dyes of the prior art includecompounds formed from the reaction of an optionally substituted anilineand an optionally substituted phenol to form an optionally substitutedbiphenyl compound. Known oxidative dye compositions typically comprise,at a concentration of from 0.01 to 0.05M, for example approximately0.025M, biphenyl compounds formed by reacting the phenol and anilinecomponents in a 1:1 ratio. Such oxidative dyes of the prior art whichcan be removed from hair by the colour removal method of the presentinvention are typically formed by reaction of a phenol and an anilineeach of which is substituted with one or more substituents selected fromhydroxyl, amino and methyl. Other similar compounds are also used asoxidative dyes and these will be well known to those skilled in the art.

Suitable dyes may be purchased from James Robinson Limited ofHuddersfield under the trade mark Jarocol.

The hair colour removal method of the present invention preferablycomprises applying to dyed hair, preferably hair dyed by the method ofthe sixth aspect, a colour removal composition comprising a nucleophile,or a precursor thereof. Preferably the colour removal compositioncomprises a sulfur-containing nucleophile, or a precursor thereof.Suitable sulfur-containing nucleophiles include thiocyanate,thioglycolic acid, thiocarbamate, carbamoylsulphinic acid and mixturesand/or salts thereof. Alternatively and/or additionally, the colourremoval composition may comprise a nucleophile precursor. One suitablenucleophile precursor is thiourea dioxide. Thiourea dioxide is notnucleophilic in itself but rearranges to form formamidine sulfinic acidwhich hydrolyses to form the nucleophilic species HSO₂ ⁻(hydroxysulfoxylate).

In especially preferred embodiments the sulfur-containing nucleophilecomprises a salt of sulphoxylic acid of formula HSO₂ ⁻⁺ M. M ispreferably hydrogen, an alkali metal or a quaternary ammonium species.Such salts may suitably be generated from formamidine sulphinic acid.Under acidic conditions this compound exists as the thiourea dioxidetautomer but under mildly alkaline conditions the formamidine tautomeris formed which hydrolyses to release HSO₂ ⁻⁺ M which is believed to bethe active dye removal agent. It is also possible to use mixedformamidine/carbamoyl sulphinic acids to generate the reactive species.

The colour removal composition comprises preferably at least 0.1 wt % ofthe sulfur-containing nucleophile or precursor thereof, for examplethiourea dioxide, more preferably at least 1 wt %, most preferably atleast 4 wt %.

Suitably the colour removal composition comprises up to 60 wt % of thesulfur-containing nucleophile or precursor thereof, for example thioureadioxide, preferably up to 45 wt %, more preferably up to 30 wt % andmost preferably up to 15 wt %.

In some preferred embodiments when the chromophone moiety D is apremetallised dye comprising a transition metal (for example cobalt orchromium), the colour removal composition further comprises asequestrant. Any suitable sequestrant known to those skilled in the artmay be used. Preferred sequestrants include N-methyl taurine,phosphonates and amine alkyl phosphonates, for example those sold underthe trade mark BriQuest and DeQuest, ethylenediaminetetraacetic acid(EDTA) and ethylenediamine disuccinic acid (EDDS).

The colour removal composition may further comprise one or more of aswelling agent, an activator, a diluent, a conditioning agent and athickener.

The sequestrant, when present, is preferably present in an amount offrom 1 to 20 wt %, more preferably 5 to 10 wt %.

Suitable swelling agents include urea.

The colour removal composition preferably comprises at least 0.1 wt %urea, preferably at least 1 wt %, more preferably at least 3 wt %, mostpreferably at least 5 wt %.

Suitably the colour removal composition comprises up to 60 wt % urea,preferably up to 45 wt %, more preferably up to 30 wt % and mostpreferably up to 15 wt %.

Suitable activators include divalent and trivalent metal species, forexample divalent and/or trivalent ions of zinc, magnesium, aluminium andcalcium. Preferably the activator includes zinc or especially magnesiumions. The divalent or trivalent ions may be provided in any suitableform. Preferably they are provided as salts, for example carbonates,sulfates, chlorides, acetates or formates. More preferably they areprovided as organic acid salts, for example formate or acetate. Suitablythe activator may be selected from zinc acetate, magnesium acetate, zincoxide, magnesium carbonate, zinc sulphate, aluminium acetate, calciumacetate and mixtures thereof. Zinc acetate and magnesium acetate areparticularly preferred.

Acetate or formate salts of divalent or trivalent metals when presentmay be used directly in the colour removal compositions of the presentinvention. Alternatively the corresponding acid and a different metalsalt may be used, for example magnesium sulphate and acetic acid.

The colour removal composition comprises preferably at least 0.1 wt % ofone or more activators, more preferably at least 1 wt %, most preferablyat least 4 wt %.

Suitably the colour removal composition comprises up to 60 wt % of oneor more activators, preferably up to 45 wt %, more preferably up to 30wt % and most preferably up to 15 wt %.

The preferred diluent is water. This suitably present in an amount offrom 10 to 90 wt %.

Suitable pH buffers include 2-amino-2-methyl-1-propanol.

Suitably the colour removal composition has a pH of from 6 to 12, morepreferably from 7.5 to 10.5, and most preferably from 8.5 to 9.5.

A preferred thickener is hydroxyethylcellulose. Preferably the colourremoval composition comprises from 1 to 20 wt % of thickeners.

In order to maximise the shelf life of the colour removal composition,it can be packaged as a two component system which could be mixedtogether shortly before use. By utilising a two pack system, it ispossible to make two liquid solutions, that when combined produce athickened product which is more suitable for use on hair. This can beachieved for example by using a cosmetically approved thickener whoseviscosity changes with pH. Suitable ingredients for the colour removalformulations can be found in the INCI list or will be well known tothose skilled in the art. Such systems are described above in relationto the packaged hair colouring compositions of the fifth aspect of thepresent invention.

In the colour removal method of the present invention, the colourremoval composition is suitably applied to the hair and maintained onthe head at a temperature of from 10 to 75° C., preferably from 20 to70° C., more preferably from 30 to 65° C.

When removing colour from human hair at temperatures above ambienttemperature a suitable hood can be employed to achieve the requiredtemperature.

Suitably complete colour removal is effected after a period of 5 to 60,for example 15 to 30 minutes.

Suitably the colour removal composition is left in the hair for a periodof from 0.1 to 60 minutes, preferably 0.5 to 30 minutes for example 1 to15 minutes.

The colour removal method of the present invention has been found to bevery effective. Hair has been found to return to its original colourprior to being dyed without any visible damage occurring. In embodimentsin which an initial bleaching step has been carried out, hair has beenfound to return to its bleached colour.

This method offers considerable advantages over colour removal methodsof the prior art which rely on bleaching the hair. Such bleaching colourremoval methods of the prior art cause considerable damage to hair(particularly in the case of hair which is repeatedly dyed andoxidatively bleached) and often do not provide the original colour.

The present invention thus provides a hair treatment method comprisingthe steps of:

-   -   (a) optionally bleaching the hair;    -   (b) dyeing the hair by applying a composition of the third        aspect; and    -   (c) optionally removing colour from the hair by applying a        colour removal composition comprising a sulfur-containing        nucleophile.

Preferred aspects of each of steps (a), (b) and (c) are described above.Steps (b) and (c) may be repeated without any significant damageoccurring to hair. Preferably steps (b) and (c) may be each repeated twoor more, preferably five or more, for example ten or more times withoutany significant increased damage to the hair being observed.

Step (a) is an optional initial bleaching step, which may be carried outusing any suitable bleaching method of the prior art. This is carriedout if it is desired to lighten the initial colour of hair prior to afirst dyeing step. However, once a first colour has been applied, thereis no need to again bleach the hair further to remove this colour asthis can be carried out in step (c). Step (a) would be repeated only ifa lighter base shade is required. Of course it will also be necessary tobleach new hair which has grown since previous colouring.

Because steps (b) and (c) can be carried out rapidly, it would bepossible for a user to dye a small portion of hair (either on or off thehead) to see exactly the colour that would be achieved and remove thiscolour if it was not desirable.

The colouring method of the present invention is highly reproducible,rapidly develops to full colour, is resistant to fade and readilyremovable, and thus offers considerable advantages over the prior art.

According to a seventh aspect of the present invention there is providedthe use of compounds of the first aspect to colour human hair. The useof the compounds of the present invention provides numerous advantagesover colouring compounds of the prior art, such as are described herein.

The present invention is represented by the following non-limitingexamples.

Percentage values herein denote the weight of a given componentexpressed as a percentage of the total weight of the composition inwhich it is present unless otherwise stated.

In these examples, suitable conditions are given for hair dyeing andcolour removal. However it will be appreciated that these conditionscould be modified as appropriate depending on the hair being treated andthe equipment available in the salon.

EXAMPLES Example 1 Synthesis of carboxymethylthiolethylsulphone dyeusing Remazol dyes as starting materials

A carboxymethylthiolethylsulphone dye may be prepared using thesynthesis route as illustrated in Diagram 1.

In the reaction scheme D is a chromophore and varies depending on whichstarting dye is used. In the present example a variety of Remazol® dyescommercially available from Dystar are used as starting materials, inparticular, Remazol Black B, Remazol Yellow GS, Remazol Orange G,Remazol Red B, Remazol Blue R, Remazol Blue B, and others mentioned inexamples herein.

Synthesis of carboxymethylthiolethylsulphone dye

An aqueous dye solution (0.1 mol/100 ml, pH 10.5) of a purified Remazol®dye is prepared. To this solution, a 0.1 mol solution of sodiumthioglycollate (pH10.5) is added by slow dripping at a temperature ofbetween 23 and 25° C.

After the addition of sodium thioglycollate, the pH of the system ismaintained at pH10.5 using sodium carbonate. The reaction is thenallowed to proceed, at 20-25° C. and pH10.5, for 5-8 hours. At the endof the synthesis, the pH of the system is reduced to below pH 2, whichprecipitates the carboxymethylthiolethylsulphone dye compounds which arethen isolated by filtration and washing.

Example 2 Synthesis of hydroxyethylthioethylsulphone dye

The hydroxyethylthioethylsulphone dye may be prepared using thesynthesis route as illustrated in Figure 2.

In the reaction scheme D is a chromophore and varies depending on whichstarting dye is used. In the present example Remazol Orange G is used asthe starting material, but other suitable sulphatoethylsulphone dyecompounds can also be used as starting materials such as Remazol Yellowand Remazol Brilliant Blue R.

0.1 mole of Remazol Orange G dye is dissolved in 150 ml of distilledwater adjusted to pH10.5 using sodium carbonate, and added to a flask.The flask is placed in a water bath. 0.1 moles of thioethanol is thenadded drop-wise, to the reaction mixture under stirring. The totaladdition time is one hour. The pH of the reaction scheme is maintainedat pH10.5 and the temperature of the reaction system 20-25° C. duringaddition of thioethanol. The reaction is then allowed to proceed at20-25° C. and pH10.5 (which is corrected as necessary using sodiumcarbonate) for 5 hours. The endpoint of the reaction is indicated by thepH remaining constant for more than 5 minutes. At this point, thehydroxyethylthioethylsulphone dye is obtained. The pH of the system isthen reduced to pH2 and KCl (35% of the total solution) is then added tothe reaction mixture in order to precipitate the dye. Filtration usingWhatman filter paper follows. The precipitate is then washed withacetone for 4-5 times (50 ml of acetone used each time) to obtain thefinal dye product.

Example 3 Synthesis of monothiosuccinate-S-ethylsulphone dye

The monothiosuccinate-S-ethylsulphone dye may be prepared using thesynthesis route as illustrated in Figure 3.

In the reaction scheme, D is a chromophore and varies depending on whichstarting dye is used. In the present example Remazol Orange G is used asthe starting material, but other suitable sulphatoethylsulphone dyecompounds can also be used as starting materials, such as Remazol Yellowand Remazol Brilliant Blue R.

0.1 moles of pure Remazol Orange G dye and 150 ml of distilled water areintroduced into a 400 ml flask and the pH adjusted to pH10.5 usingsodium carbonate. The flask is placed in a water bath. 0.1 moles ofthiosuccinic acid is then added dropwise with stirring. The additiontime is 1-1.5 hours. The pH of the reaction system is maintained atpH10.5 and the temperature of the reaction system is 20-25° C.throughout the addition of thiosuccinic acid.

The reaction is then allowed to proceed, at 20-25° C. and pH10.5 (whichis adjusted as necessary using sodium carbonate) for 6 hours. Using 6NHCl, the pH of the system is then reduced to pH2. KCl (35% of the totalsolution) is then added to the reaction mixture in order to precipitatethe dye. Filtration using Whatman paper follows. The precipitate is thenwashed with acetone for 4-5 times (50 ml of acetone is used each time)to obtain the final dye product.

Example 4

An acrylamido dye precursor of general formulaAr—N═N—[H-acid]-NH—(C═O)—CH═CH₂— illustrative of class (X) definedabove—was prepared as follows:

Aniline (0.1 mole) was dissolved in 0.1 molar HCL (50 ml), cooled in anice-bath to 0-5 C and then reacted with nitrous acid (1.2 moles of NaNO₂dissolve in minimum 0.1M HCl dripped in slowly over 30mins.)—diazotisation was complete at this stage. Excess nitrous acid wasremoved by adding 0.5 moles of urea.

Ar—NH₂+HONO(HCl)Ar—N₂ ⁺Cl⁻+H₂O

-   -   Diazonium salt

The above diazonium salt was then added slowly, at 0-5° C., to anaqueous alkaline solution of H-acid (1 mole ofnaphthalene-1-amino-2-hydroxy-3,6-disulphonic acid) buffered at pH 10with excess sodium carbonate; instantly a bright bluish red colour wasformed in solution. The reaction was stirred for a further 60 minutes.Still maintaining the pH at 10 and the temperature at 0-5° C., acryloylchloride was solely dripped into the stirred mixture. Reaction continueda further 1 h under these conditions—at this stage the system was testedfor free aromatic amine (Ehrlich test) and if none was detected theproduct isolate by the addition of sufficient saturated salt solution.Filtration and washing with saturated salt solution and ethanol, thendrying completed the process. The isolated acrylamido dye was found tohave a purity greater than 95% (HPLC).

The brilliant, bluish-red dye precursor, of formula X, has the followingstructure:

This dye precursor may be onward reacted as described above to make adye compound of formula (I) of the invention.

Example 5

Dye solutions can be made up using compounds prepared according toExample 1 and packaged in a suitable bottle-type package.

Ingredients % 5a - Auburn Dye Urea 10.00 Cocamidopropyl Betaine 0.80 Dyeprepared according to Example 1 using Remazol Orange G 0.23 Dye preparedaccording to Example 1 using Remazol Yellow GS 0.42 Dye preparedaccording to Example 1 using Remazol Black B 0.35 Thioglycolic Acid 80%2.5 Triethanolamine 99% 50.74 Ammonium Hydroxide 29% 9.00 Water To 1005b - Light Brown Dye Urea 10.00 Cocamidopropyl Betaine 0.80 Dye preparedaccording to Example 1 using Remazol Red B 0.010 Dye prepared accordingto Example 1 using Remazol Yellow GS 0.226 Dye prepared according toExample 1 using Remazol Blue B 0.678 Thioglycolic Acid 80% 2.5Triethanolamine 99% 50.74 Ammonium Hydroxide 29% 9.00 Water To 100 5c -Champagne Blonde Dye Urea 10.00 Cocamidopropyl Betaine 0.80 Dye preparedaccording to Example 1 using Remazol Red 5B 0.023 Dye prepared accordingto Example 1 using Remazol Golden 0.465 Yellow GR Dye prepared accordingto Example 1 using Remazol Blue BS 0.512 Thioglycolic Acid 80% 2.5Triethanolamine 99% 50.74 Ammonium Hydroxide 29% 9.00 Water To 100 5d -Auburn Dye Urea 10.00 Cocamidopropyl Betaine 0.80 Dye prepared accordingto Example 1 using Remazol Red B 0.023 Dye prepared according to Example1 using Remazol Golden 0.42 Yellow GS Dye prepared according to Example1 using Remazol Blue B 0.35 Thioglycolic Acid 80% 2.5 Ammonium Hydroxide29% 11.48 Water To 100 5e - Light Brown Dye Urea 10.00 CocamidopropylBetaine 0.80 Dye prepared according to Example 1 using Remazol Red RS0.010 Dye prepared according to Example 1 using Remazol Yellow G 0.226Dye prepared according to Example 1 using Remazol Blue B 0.678Thioglycolic Acid 80% 2.5 Ammonium Hydroxide 29% 11.48 Water To 100

Example 6

Dye solutions can be made up using compounds prepared according toExample 1 and packaged in a suitable bottle-type package.

Ingredients % 6a - Plum Silver Urea 10.0000 Cocamidopropyl Betaine0.8000 Dye prepared according to Example 1 using Remazol Golden YellowRNL 150% 0.0632 Dye prepared according to Example 1 using RemazolBrilliant Red F3B gran 0.0628 Dye prepared according to Example 1 usingRemazol Black B 0.0408 Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide29% 6.2000 Water To 100% 6b - Golden Brown Urea 10.0000 CocamidopropylBetaine 0.8000 Dye prepared according to Example 1 using Remazol GoldenYellow RNL 150% 1.3924 Dye prepared according to Example 1 using RemazolOrange 1.0000 Dye prepared according to Example 1 using Remazol BlackGWF 0.7116 Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide 29% 6.2000Water To 100% 6c - Aubergine Urea 10.0000 Cocamidopropyl Betaine 0.8000Dye prepared according to Example 1 using Remazol Golden Yellow RNL 150%0.1024 Dye prepared according to Example 1 using Remazol Brilliant RedF3B gran 1.0072 Dye prepared according to Example 1 using Remazol BlackB 0.9920 Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide 29% 6.2000Water To 100% 6d - Candy Floss Urea 10.0000 Cocamidopropyl Betaine0.8000 Dye prepared according to Example 1 using Remazol Brilliant RedF3B gran 0.1036 Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide 29%6.2000 Water To 100% 6e - Chestnut Brown Urea 10.0000 CocamidopropylBetaine 0.8000 Dye prepared according to Example 1 using Remazol GoldenYellow RNL 150% 1.5368 Dye prepared according to Example 1 using RemazolBrilliant Red F3B gran 0.9924 Dye prepared according to Example 1 usingRemazol Black GWF 0.9872 Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide29% 6.2000 Water To 100% 6f - Mid Brown Urea 10.0000 CocamidopropylBetaine 0.8000 Dye prepared according to Example 1 using Remazol ®Golden Yellow RNL 150% 0.8088 Dye prepared according to Example 1 usingRemazol ® Brilliant Red F3B gran 0.4136 Dye prepared according toExample 1 using Remazol ® Black GWF 0.3948 Thioglycolic Acid 80% 6.0000Ammonium Hydroxide 29% 6.2000 Water To 100% 6g - Burgundy Desire Urea10.0000 Cocamidopropyl Betaine 0.8000 Dye prepared according to Example1 using Remazol Golden Yellow RNL 150% 1.4908 Dye prepared according toExample 1 using Remazol Brilliant Red F3B gran 1.5164 Dye preparedaccording to Example 1 using Remazol Black GWF 0.2988 Thioglycolic Acid80% 6.0000 Ammonium Hydroxide 29% 6.2000 Water To 100% 6h - TangerineSpark Urea 10.0000 Cocamidopropyl Betaine 0.8000 Dye prepared accordingto Example 1 using Remazol Golden Yellow RNL 150% 0.5344 Dye preparedaccording to Example 1 using Remazol Brilliant Red F3B gran 0.1900 Dyeprepared according to Example 1 using Remazol Orange 3R Spec gran 1.0476Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide 29% 6.2000 Water To 100%6i - Midnight Black Urea 10.0000 Cocamidopropyl Betaine 0.8000 Dyeprepared according to Example 1 using Remazol Orange 3R Spec gran 1.0264Dye prepared according to Example 1 using Remazol Black B 3.9836Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide 29% 6.2000 Water To 100%6j - Chocolate Brown Urea 10.0000 Cocamidopropyl Betaine 0.8000 Dyeprepared according to Example 1 using Remazol Golden Yellow RNL 150%0.5700 Dye prepared according to Example 1 using Remazol Orange 3R Specgran 0.9844 Dye prepared according to Example 1 using Remazol Black GWF0.9740 Thioglycolic Acid 80% 6.0000 Ammonium Hydroxide 29% 6.2000 WaterTo 100% 6k - Harvest Blonde Urea 10.0000 Cocamidopropyl Betaine 0.8000Dye prepared according to Example 1 using Remazol Golden Yellow RNL 150%0.0992 Dye prepared according to Example 1 using Remazol BrilliantYellow 4GL 0.0992 Dye prepared according to Example 1 using RemazolOrange 3R Spec gran 0.0780 Thioglycolic Acid 80% 6.0000 AmmoniumHydroxide 29% 6.2000 Water To 100% 6l - Strawberry Blonde Urea 10.0000Cocamidopropyl Betaine 0.8000 Dye prepared according to Example 1 usingRemazol Brilliant Red F3B gran 0.0208 Dye prepared according to Example1 using Remazol Golden Yellow RNL 150% 0.0622 Thioglycolic Acid 80%6.0000 Ammonium Hydroxide 29% 6.2000 Water To 100%

Percentage values herein, including in relation to Examples 5 and 6,denote the weight of a given component expressed as a percentage of thetotal weight of the composition in which it is present.

Any of the compounds prepared according to Examples 1 to 4 can besubstituted for the compounds in the dye compositions of Examples 5 and6 above. In particular, the packaged hair colouring compositions of theexamples provide improvements in terms of consumer acceptance since noadmixing of ingredients is necessary before dyeing, and improved washfastness.

The compositions of Examples 5 and 6 are merely illustrative of theshades which can be produced, in accordance with the present invention.Essentially there is no limit to the shades which can be produced.

The compositions of Example 6 have a higher thioglycolic acid contentthan the compositions of Example 5 and may be especially suitable inorder to achieve a high level of reacted-on dye on the hair, in order toachieve a strong coloration effect and/or to obtain rapid coloration.Rapid reaction to the hair, and hence rapid coloration, is believed tobe promoted by a higher level of thioglycolic acid.

An aim of the invention is to achieve the desired coloration withquantitative reaction of the dye molecules applied (i.e. exhaustion ofdye molecules); thus with no wash-off of dye molecules. Of course thisis an idealised aim and take-up may be affected by many things, but theamount of thioglycolic acid is believed to be an important factor.

Example 7

The compositions of Examples 5 and 6 may typically be applied using thefollowing regime:

-   -   Rub colouration mixture into hair and leave at 25° C. for 10        minutes using a liquor ratio of 2.5:1 (2.5 g of preparation        mixture:1 g hair tress)    -   Rinse with cold or warm water    -   After-treatment: 10 minutes at 25° C. using 2.5 g (same liquor        ratio as above) of a 30 g/l Hydrogen Peroxide soln (36%), pH of        approximately 5.    -   Rinse with water    -   Shampoo    -   Rinse with water    -   Dry

Example 8a

A sample of hair having an initial bleached blonde appearance wastreated as follows.

Part 1 Part 2 37.04% Urea 88.16% Water 3.70% Laurylamidopropylbetaine2.52% Thioglycollic acid 37.04% Water 2.52% Sodium sulphite 18.52% 1part Remazol Brilliant 4.28% 2-amino-2-methyl-1- Red F3B propanol 1 partRemazol Golden Yellow RNL 1 part Remazol Brilliant Orange 3R 3.70%Hydroxyethylcellulose 2.52% Hydroxyethylcellulose

Percentage values in the table above denote the weight of a givencomponent expressed as a percentage of the total weight of thecomposition of the part in which it is present.

-   -   Prepare hair treatment mixture, by mixing 3.2 g of part 1 and        7.9 g of Part 2.    -   Brush mixture into hair and leave at 40° C. for 15 minutes using        a liquor ratio of 2.5:1 (2.5 g of preparation mixture:1 g hair        tress).    -   Rinse with warm water.    -   Massage an after-treatment solution of 30 g/l hydrogen peroxide        soln (36%) using same liquor ratio as above.    -   Rinse with water    -   Shampoo    -   Rinse with water    -   Dry as required

The resulting hair was a bright red colour that was found to exhibit novisible fade or colour change after 20 shampoo washes.

Example 8b

A sample of hair having an initial bleached blonde appearance wastreated as follows.

Part 1 Part 2 37.04% Urea 88.16% Water 3.70% Laurylamidopropylbetaine2.52% Thioglycollic acid 37.04% Water 2.52% Sodium sulphite 18.52% 1part Remazol Brilliant 4.28% 2-amino-2-methyl-1- Red F3B propanol 1 partRemazol Brilliant Yellow 4GL 1 part Remazol Brilliant Orange 3R 3.70%Hydroxyethylcellulose 2.52% Hydroxyethylcellulose

Percentage values in the table above denote the weight of a givencomponent expressed as a percentage of the total weight of thecomposition of the part in which it is present.

-   -   Prepare hair treatment mixture, by mixing 3.2 g of part 1 and        7.9 g of Part 2.    -   Brush mixture into hair and leave at 40° C. for 15 minutes using        a liquor ratio of 2.5:1 (2.5 g of preparation mixture:1 g hair        tress).    -   Rinse with warm water.    -   Massage an after-treatment solution of 30 g/l hydrogen peroxide        soln (36%) using same liquor ratio as above.    -   Rinse with water    -   Shampoo    -   Rinse with water    -   Dry as required

The resulting hair was a bright orange colour that was found to exhibitno visible fade or colour change after 20 shampoo washes.

Example 8c

A sample of hair produced from example 8b having an initial brightorange appearance was treated as follows.

Part 1 Part 2 50% Urea 92.86% Water 25% Thiourea dioxide 5.84%2-amino-2-methyl-1-propanol 25% Zinc acetate 1.08%Laurylamidopropylbetaine 0.22% Hydroxyethylcellulose

Percentage values in the table above denote the weight of a givencomponent expressed as a percentage of the total weight of thecomposition of the part in which it is present.

-   -   Prepare hair treatment mixture, by mixing 2.0 g of part 1 and        9.3 g of Part 2.    -   Brush mixture into hair and leave at 30° C. for 25 minutes using        a liquor ratio of 2.5:1 (2.5 g of preparation mixture:1 g hair        tress).    -   Rinse with warm water.    -   Dry as required

The resulting hair was a blonde colour with no hint of the previouscolour and with little or no damage.

Example 8d

A process where hair treated in example 8c is then coloured using themethod in example 8b to give bright orange coloured hair which was foundto exhibit no visible fade or colour change after 20 shampoo washes.

Example 8e

A process where hair treated in example 8d is then treated with thecolour removal system as described in example 8c to give a blondecoloured hair with little or no damage.

Example 8f

The process of example 8c was repeated except that the colour removalcomposition was left on the hair for 15 minutes at a temperature of 60°C. Again, the resulting hair was a blonde colour with no hint of theprevious colour and with little or no damage.

1. A compound of formula (I)D-L-CHQ-CH₂—SR   (I) wherein D is a chromophore; L is a linking groupselected from SO₂, NHCO, and NHSO₂; Q is a hydrogen or halogen atom; andR is selected from C₁-C₄ alkyl, (CH₂)_(n)COOH, (CH₂)_(n)CONH₂,(CH₂)_(n)SO₃H, (CH₂)_(n)COOM, (CH₂)_(n)PO₃H, (CH₂)_(n)OH, (CH₂)_(n)SSO₃⁻, (CH₂)_(n)NR¹ ₂, (CH₂)_(n)N⁺R¹H₂, (CH₂)_(n)NHCOR¹, PhSSO₃ ⁻, PhSO₃H,PhPO₃H, PhNR¹ ₂, PhN⁺R¹ ₃, (CH₂)₂CH(SH)R¹(CH₂)₃COOH, and

n is an integer in the range of 1 to 4 wherein within the same moleculeeach n is not necessarily the same integer; M is a cation of an alkalineearth metal, alkali metal, NH₄₊ or NR¹ ₃ ⁺; and R¹is C₁-C₄ alkyl.
 2. Acompound according to claim 1 wherein Q is hydrogen.
 3. A compoundaccording to claim 1 wherein L is SO₂.
 4. A compound according to claim1 wherein the group SR in formula (I) is SCHR²R³; wherein R² is selectedfrom (CH₂)_(m)COOX, (CH₂)_(m)SO₃X, (CH₂)_(m)NH₂, (CH₂)_(m)NR⁴R⁵,(CH₂)_(m)NHCOR⁴ and (CH₂)_(m)CH(COOX)NH₂; wherein m is an integer offrom 0 to 3, and X is selected from hydrogen, an alkali metal, a C₁ toC₄ alkyl group and a substituted or unsubstituted ammonium salt; R⁴ is aC₁ to C₄ alkyl group and R⁵ is selected from hydrogen and a C₁ to C₄alkyl group; and R³ is selected from hydrogen, an alkyl group having 1to 4 carbon atoms, an ester, an acid, an amide, an amine residue or analcohol residue.
 5. A compound according to claim 1 having the structureof formula (III) or formula (IV):D-SO₂—CH₂—CH₂—SCH₂COOH   (III)D-SO₂—CH₂—CH₂—SCH₂CH(COOH)NH₂   (IV) or an ester or salt thereof.
 6. Amethod of preparing a compound as claimed claim 1, the method comprisingreacting a compound of formula (X) or (X′) with a thiol of formula (XI):

wherein R, D and L are as defined in claim 1 and Y is a leaving group.7. A composition for colouring a material comprising a compound asclaimed in claim 1 and a diluent or carrier.
 8. A composition accordingto claim 7 wherein the compounds of claim 1 are formed in situ.
 9. Acomposition according to claim 7 which further comprises a thiolselected from thioglycolic acid, thiolactic acid, dihydrolipoate,thioglycerol, mercaptopropionic acid, cysteine, N-substituted cysteines,cysteamines, N-substituted cysteamines, thioethanol and 1-thiopropane3-sulfonate.
 10. A composition according to claim 7 which furthercomprises urea.
 11. A method of dyeing fibres, the method comprisingapplying to the fibres a composition as claimed in claim
 7. 12. A methodof removing colour from dyed hair, the method comprising applying to thehair a colour removal composition comprising a sulfur-containingnucleophile or a precursor thereof.
 13. A method according to claim 12wherein the sulfur-containing nucleophile comprises a salt ofsulphoxylic acid of formula HSO₂ ⁻⁺M wherein M is selected fromhydrogen, an alkali metal and a quaternary ammonium species.
 14. Amethod of removing colour from dyed hair, the method comprising applyingto the hair a colour removal composition according to the method ofclaim
 7. 15. A hair treatment method comprising the steps of: (a)optionally bleaching the hair; (b) dyeing the hair by applying acomposition as claimed in claim 7; and (c) optionally removing colourfrom the hair by applying a colour removal composition comprising asulfur-containing nucleophile.